1. Field of the Invention
The present invention relates to an energetic neutral particle lithographic apparatus and technique for replicating patterns with submicron linewidths, where the spacing between the mask and substrate is greater than 1000 times the minimum linewidth.
More particularly, the present invention relates to an energetic neutral particle lithographic apparatus and technique for replicating patterns with submicron linewidths, where the apparatus includes generating a beam of small energetic atoms or molecules, contacting a substrate including a beam sensitive coating and a mask with the beam, where a spacing between the mask and the substrate is greater than 1000 times the minimum linewidth, and developing the coating to produce a patterned substrate.
2. Description of the Related Art
Proximity lithography is a method of pattern reproduction in which energetic radiation, x-rays, electrons or ions, irradiate a mask containing a pattern of opaque and transmissive regions. The radiation pattern consisting of the radiation that passes through the transmissive regions exposes a sensitive film on a substrate positioned in close proximity to, but not touching, the mask. After exposure, the film is subjected to a developer that removes either the exposed or the unexposed regions thereby producing either a positive or negative copy of the mask pattern. X-ray proximity lithography technology has been developed for manufacturing integrated circuits with feature sizes down to about 50 nm while, because of their shorter wavelength and hence weaker diffraction, electrons and ions have been explored for printing sub-50 nm features.
Unlike x-rays, however, these charged particles are easily deflected by fixed and mobile charge in the mask and on the substrate. This leads to blurring and imprecise pattern placement in the printed image that limits the utility of electrons or ions for high resolution printing. This problem is particularly difficult if the features are extremely small and/or the spacing between the mask and wafer is large, particularly with spacing between the mask and substrate is more than 1000 times the minimum feature size in the mask.
Thus, there is a need in the art for a lithographic apparatus and process capable of making submicron devices, especially devices having a size of 50 nm or less, 20 nm or less, 10 nm or less.